assume cs:codesg
codesg segment
   mov ax, cs
   mov ds, ax
   mov ax, 0020h
   mov es, ax
   mov bx, 0
   mov cx, 17h
s: 
   mov al, [bx]
   mov es:[bx], al
   inc bx
   loop s

   mov ax, 4C00H
   int 21H

codesg ends

end
